It has become increasingly accepted that successful intervention and treatment of Alzheimer's disease (AD) relies on characterization of decline in cognitive function in the earliest stages that can be reliably detected. The most sensitive and specific method of detecting the "preclinical" stage of AD, including subtle distinctions between "normal aging" and mild cognitive impairment (MCI), is through multifaceted cognitive assessment. At present, the majority of multi-center research and controlled trials utilize paper-based forms of well-established tests (Auditory Verbal Learning Test (AVLT), Trail Making, Category Fluency, etc.). However, multifaceted cognitive assessment by arrays of paper-based forms and kits is inefficient, error prone and does not meet the needs for standardization across multiple sites. Computerized versions of these tests have rarely been applied in AD research or clinical trials. Even in the current NIA-sponsored Alzheimer's Disease Neuroimaging Initiative (ADNI), paper versions are used in all 46 centers. Wide acceptance of computerized versions of these tests will require a versatile platform as well as a large normative database that stringently excludes subjects with MCI. The project objective is to develop a Computerized Early Dementia Assessment System (CEDAS) that provides a master set of the most widely accepted and applied cognitive tests, sufficient to meet the requirements of a minimum of 75 percent of controlled clinical trials as well as related research. A large normative database (N=600) will be compiled in a geographically diverse sample of subjects matching the demographic composition of the national census and meeting stringent inclusion and exclusion criteria. The CEDAS will be uniquely capable of administering a wide range of tests in elderly subjects due to an advanced, interactive, dual-display and control architecture that integrates a human examiner, enabling precise control of every step of the administration process. During a testing session, an examiner can "pause", repeat (or supplement) digitized instructions, score both simple and complex verbal report, as well as overt behavioral performance, thus enabling computerization of tests not possible on single-display systems. The CEDAS will also host an advanced, computer-assisted, telephonic assessment module that will support cost-effective remote assessment, large cohort tracking, and integrate the processes of screening and recruitment for population-based, epidemiological studies. Advanced CEDAS utilities will also include: (a) integral, multimedia-based, examiner training for all tests;(b) automated project reporting and documentation;(c) automated patient enrollment tracking and scheduling;(d) comprehensive multilingual support;and (e) integrated web-based services, including automated electronic database transfer. To ensure relevance of the assessment battery as well as system functions for application in controlled trials, multi-center research projects, or clinical practice, CEDAS development will be guided by an Advisory Committee of leading authorities in the field, including the Chair of the ADCS Instrument Committee. PUBLIC HEALTH RELEVANCE: The CEDAS will provide a highly efficient, computerized method of performing sensitive and specific cognitive assessment of early stage AD. The CEDAS normative database will be the largest of its kind and is critically needed for distinguishing normal aging from "preclinical" AD. The CEDAS will be applied in clinical trials and wide-ranging research to find treatments for Alzheimer's disease in the early stage. Integration of a flexible, computerized telephonic assessment module will provide an associated means of early stage assessment as well as an automated means of screening and tracking participants in clinical trials and large scale epidemiological studies of AD.